The APA calls it “harmful” and says it could lead to homophobia and sexual harassment.

“The main thrust of the subsequent research is that traditional masculinity – marked by stoicism, competitiveness, dominance and aggression – is, on the whole, harmful,” the organization said in a news release.

Men! The American Psychological Association wants you to be more like Commodus, left, than Maximus.

It goes on to reveal that “traditional masculinity is psychologically harmful and that socializing boys to suppress their emotions causes damage that echoes both inwardly and outwardly.”

The APA research also coins the term “masculinity ideology,” which it says hurts men and boys.

“Traditional masculinity ideology has been shown to limit males’ psychological development, constrain their behaviour, result in gender role strain and gender role conflict, and negatively influence mental health and physical health,” the report warns.

Among the pillars of “masculinity ideology” are “anti-femininity, achievement, eschewal of the appearance of weakness, and adventure, risk, and violence.”

Taciturn Clint Eastwood in Dirty Harry. Do NOT be like him, the American Psychological Association says. WARNER BROS.

And that means masculine boys devote their energy towards “disruptive behaviours” like homophobia, bullying and even sexual harassment.

Instead, boys should be striving for academic excellence, the APA says.

“Though men benefit from patriarchy, they are also impinged upon by patriarchy,” said Ronald F. Levant, EdD, a professor emeritus of psychology at the University of Akron and co-editor of the APA volume The Psychology of Men and Masculinities.

So, what to do?

The APA says psychologists should address their own biases when treating boys and men.

Address how “power, privilege, and sexism work both by conferring benefits to men and by trapping them in narrow roles,” the report says.